Single-inclusive production of large-pT charged particles in hadronic collisions at TeV energies and perturbative QCD predictions

Abstract

The single inclusive spectrum of charged particles with transverse momenta pT = 3 – 150 GeV/c measured at midrapidity by the CDF experiment in proton-antiproton \( \left( {p - \bar{p}} \right) \) collisions at \( \sqrt {s} = 1.96{\text{ TeV}} \) is compared to next-to-leading order (NLO) perturbative QCD calculations using the most recent parametrizations of the parton distributions and parton-to-hadron fragmentation functions. Above pT ≈ 20 GeV/c, there is a very sizeable disagreement of the Tevatron data compared to the NLO predictions and to xT-scaling expectations, suggesting a problem in the experimental data. We also present the predictions for the pT-differential charged hadron spectra and the associated theoretical uncertainties for proton-proton (p-p) collisions at LHC energies \( \left( {\sqrt {s} = 0.9 - 14{\text{ TeV}}} \right) \). Two procedures to estimate the charged hadron spectra at LHC heavy-ion collision energies \( \left(\sqrt {s} = 2.76 \right) \), 5.5 TeV) from p-p measurements are suggested.